Conventional offshore drilling techniques control pressure inside the wellbore by utilizing the hydrostatic pressure generated by drilling fluid circulated through the well. When using only hydrostatic pressure to control wellbore pressure, it can be difficult to compensate for pressure changes because pressure in the wellbore may be adjusted only by changing the density or specific gravity of the drilling fluid, or by adjusting the mud pump circulation rate. But these methods are incapable of addressing sudden unexpected changes in pressure, as circulation rate induced pressure changes are small, and it can take hours to change the makeup of the drilling fluid. Newer techniques, such as underbalanced drilling and managed pressure drilling, address this problem by closing the annulus and utilizing pressure management devices to control wellbore pressure.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.